Electric heater.



H. W! DENHARD.

ELEQTRlC HEATER.

APPUCAIION' FILED on. 17, 1910.

Patented July 13, 1915.

2 SHEETSSHEET I.

HI WI ELECTRIC HEATER.

APPLICATION FILED 0CT.'|7'| 19H).

Patented July 13, 1915.

2 SHEETS-SHEET 2 J STATES PATENT OFFICE.

HARRY W. DENHARD, OF MILWAUKEE, WISCONSIN, ASSIGNOB TO THE CUTLER- HAMMER MFG.

00., F MILWAUKEE, WISCONSIN, A-GORPORATION OF WIS- consm. I

I ELECTRIC HEATER.

1,145 977. Specification of Letters Patent. Patented July 13, 1915.

v Application and October 17, 1910. Serial No. 587,859.

To all whom it may concern:

Be it known that I, HARRY W. DENHARD,

, a citizen of the United States,'residing at Milwaukee, in the county of Milwaukee and State of \Visconsin, have invented new and -useful Improvements in Electric Heaters, of :-which the following is a full, clear, concise, v and exact. description, reference being had "'to the accompanying drawing, forming a part bf this specification.

" This invention relates to improvements m' .illelectric heaters. Y

ing appliances and the like, but it should be understood that it is capable of use in various other relations. 4

Electric cooking appliances are usually provided with a heating coil which .is constructed or arranged so that a cooking uten- '20 sil may be placed in a position adjacent the coil to be heated thereby. It is frequently desirable to regulate and vary the heat applied to the utensiland to attain this end it 1 is customary to vary the current through the coil and thereby regulate the heat generated.

When a resistance is used to vary the current it causes a waste of energy and since it is generally varied in a' few steps it does not permit of agradual variation of the heat generated. Moreover, when a resistance is employed the heat cannot be reduced in-.

stantly or quickly without removing the utensil, which is not always convenient or desirable and in some'appliances is lmpos- .sible. The reason for this difficulty is that .theheating coil and its surrounding structure retains the heat for a prolonged period :aluring which time the contents of the utensi'l may be overheated.

40 One of the objects of the present invention is to provide improved means by which the heat may be readily regulated.

Another object is to provide means by which the heat applied to the utensil maybe I which is vertically adjusted with the teleinstantly reduced.

Another object is to provide means by which the heat applied to the utensil may be gradually varied.

A further object is to provide a heater which in itself is a unitary structure capable of-use either alone or in conjunction with other appliances. I i A still further; object of; the invention :is to provide a' heating appliance in which the a It is especially adapted foruse with cookto support a utensil.

heat delivered to the utensil may be regu lated by the manipulation of a single controlhng means.

In accordance with my invention I so arrange or mount the heating coil that its relation to the object to be heated, either me- .diately or immediately, may be varied as occasionmay require. In the case of cookng appliances, I preferably arrange the coil 1n a structure which constitutes .a heating unit, which unit-is mounted'so'as to be movable relatively to the utensil and I provide means by which it may be readily moved so as to vary the heat applied to the utensil.

Various adaptations and embodiments of purview of my .improve- @111 ese views Fig re 1 illustrates sid elevation of one form of my improved heat mg device, arranged to heat-achafing disli, or similar.utensil. Fig. 2 shows a partial sectional view of this formof'niy improved heating. device. Fig. 3 shows a partial sectional view on line 3 3' of Fig. 2,. of one form of mechanism which may be used to vary the position of the heating unit. Fig! 4 shows a partial sectional view 1 of this mechanism on line 4.-4 of Fig. 3.

In the construction shown in the drawing I provide a frame having'a ring 1 adapted This frame has suitable legs 2 and supports within it, a central pedestal 3. 'Adapted to be adjusted vertically within this pedestal by suitable means,'hereinafter described, is a telescoping member 4. Upon the upper end of this tele- 'scoping' member is mounted a' heating unit 5 of aconstruction hereinafter described,

scoping member 4 and is guided in such .movement by suitable guides;;6 formed on the inner'surface of the utensil supporting ring 1.

One means which I maytemploy for vary- I ing the elevation of the heating units-with respect to the utensil to beheated, 'com-' prises a shaft 7, having a. or handle 8 and journaled in the pedes'tall3, and arac'k and pinion mechanism'associated with this shaft for varying the elevation of the telescoping member 4 and the heating .unit 5 carried thereby. Suitable slots 9 and 10 are provided in the telescoping member so that in its vertical movement it may pass the shaft 7. -At a point between'the ends and within. the'telescoping member 4, the

v shaft? is screw threaded at 11. Cooperating with this thread 'is an internally threaded pinion 12 having a travel on the thread limited in one direction by a collar 13 fixed to the shaft and rotating with the same. Immediately adjacent the pinion 12 and separated from it by a soft metal Washer 14 if desirable, is a ratchet wheel 15 .provided with a spring held pawl 16 of the usual type. This pawl is mounted on a stud '17 carried by thepedestal 3 and extending through the slot 10 in the inner telescoping member 4. 'Fixed to the shaft '7,

or integral with it, and immediately adjacent the ratchet wheel 15 is a collar 18. 7 All ,of these elements 12, 13, 14 and'18 may be 1 within the telescoping member 4.

Fixed to the inner, surface of the telescoping'member 4 is a longitudinally ex tending rack 19 engagingwith the pinion 12 and upon the rotation of said pinion adapted to raise or lowerthe telescoping member 4 and the heating unit 5 carried thereby, to vary the position of the latter as desired.

, retaining plate 24 and a disk 25 of asbestos maybe provided in order to prevent the downward radiation and consequent loss of heat. The heating means may, however, as-

- sume any desired form.

The frame which supports the unit 5 may be constructed of suitably stamped metal.

It. preferably comprises a utensil support ing ring 1, a pedestal 3 in which the telescoping member is adapted to be raised or lowered, and supporting legs 2. -The utensil supporting ring 1 is preferably so stamped that it has ears 26 bent downward and adapted to overlap flanges 27 formed on the upper ends of the legs 2. According to a preferred construction, the unit guides 6 are formed by bending a portion of the ears 26 inward and I also preferably form lugs 28 upon the guides and rivet these lugs to the legs 2. Beneath the utensil supporting ring 1, the pedestal 3 is centrally supported by rods 29 fixed to the pedestal 3 and the legs'2 by anysuitable means. The lower ends of the legs 2 are bifurcated at 30 so that if it is desired to use my heating device in conjunction with- -another appliance, such as a chafing dish 31 for example,

they may straddle the frame pieces 32 of the chafing dish, or other appliances, to center the heatingdevice accurately and hold it securely in the frame. Thus I am able to obtain a structure which is capable of being used independently as a unitary device, in this instance resting on a suitable support, such, as a table, and which is, if desirable, also capable of being used with another appliance without any change whatsoever to the construction of either.

I w ll now describe'the operation of this emb'fl iment of my invention. Let it be supposed that it is desired to 'heat a material contained in any suitable receptacle and that the heating unit is in its lowest position in the frame. The utensil is placed upon the ring 1 and the line conductors are connected to the plugs 22 ofthe heating unit 5. Heat is thereupon radiated from the. heating unit, but at such a'distance from the utensil as to-havelittle heating effect upon 1t. If an increase in heatin effect is desired it is acconiplishcd by slmply turning the knob 8 so as to rotate the threaded shaft 7 to the right in Fig. 4. On this rotation of the shaft 7 and its thread 11, the pinion 12 engaging with the thread moves transversely along the same until it abuts against the ratchet wheel 15, forcing the latter along the shaft until it in turn abuts against the collar 18 and engagesfrictionally therewith.- Thus a frictional engagement of the three parts is made so that they all turn together. As the shaft is further rotated, the pinion 12 is rotated with it. Since the pinion 12 meshes with the rack 19, the rack is moved upward as the pinion is rotated,"

carrying with it the telescoping member 4 and the heating unit 5 until theunit reaches the desired position beneath the object to be heated. During this upward movement of the rack the pawl 16 slides over the teeth of the ratchet wheel 15 forming, through its engagement between the teeth at each step, a lock to prevent the downward movement of the heating unit. Through the provision r of, this means it is impossible for the heating unit, after it has been moved to a certain position, to be forced downward by any pressure applied to it or any weight resting upon it until the shaft 7 is turned in the reverse direction.

Let it now be supposed that it is desired to decrease the amount of heat which is being applied to the utensil resting upon the ring 1. By rotating the knob 8 in the reverse direction, that is toward "the left, the shaft 7 is oppositely rotated. The thread 11 is therefore so rotated as to cause the pinion 'ii upon the. principle ."of my invention and I "ratchet wheel and the .collar' 18 The pinion 12' is thereby disengaged from the ratchet wheel ,15 'and the latter is thereby released,{whereupon=the weight of the incased unit'g; ,5-;.wi11 be sufliciently great to cause it tojfallby gravity carrymg with it the'rack19-',The pinion 12-is turned by this ovement of the rack and caused rlctionally, When this occurs the downward moveto'trav'elalon'g the thread 11 to rengage the ment of the-rack 19, and consequentl the unit 5 is "stopped. The steps in the own-.

ward movement-of the unit are dependent for their- Lnumber and length upon the amount that the shaft 7 is turned. For example, if the shaft is turned sufliciently far the heatindevice will be free 'to fall to its position. 0 least heating effect in a single .ra id' 1novement,.while, if the shaft 7 is only turned a trifle at a time the device .Imay beflowered gradually to provide a numberof gradations in heatin effect. In

eachposition" the unit, just as m elevating it, is locked by the pawl 16. Under certain circumstances it may be advisable to provide J-a positive lowering action rather than to ".rely upon the pull of gravity upon the unit for the downward movement. To accomplish this, I provide the collar 13 fixed to the shaft 7, with which the pinion 12 will engage. frictiOnally-when the shaft is turned sufliciently far toward the left. As the shaft .is thus turned,-' the pinion 12 is locked to M the collar13 in sucha manner that during the continued rotation of the shaft to the left the pinion rotateswith it and afl'ords a positive lowering means for the rack with which it engages. 1

It is obvious that by the use of my improved heating device that the heat applied tothe utensil-to be heated may be increased or decreased at will. Itjis apparent also that this heat may be reduced instantaneously when the unit is lowered, since the radiating range of the unit isalways the same. Thus I am able to do away with the deleterious 6 effects of the heat stored in the resistance unit, which are present in all devices wherein the unit is stationary, and 1am able to regulate more delicately the heat applied to the material to be heated, than has been possible with other electrical heating, devices heretofore employed. When desirable ,I may, however, combine these two methods of varying the heat and-in this manner obtain' an even more delicate adjustment of the heat. It obvious that the heater may have any desired range of movement and thatit'maybe of any desiredtype.

It is apparent to one skilled in the art that other constructions than that described in this application may be devised to operate the position of said heatingdevice.

I I claim as new and desire to secure by Letters Patent, is.

1. In combination, a chafing dish frame, a heating device a frame therefor independent of said chafing dish frame and having legs arranged to straddle the legs of said chafing dish frame, and means for varying 2. In combination, a frame having radially extending bifurcated feet, a pedestal centrally located in said frame, a heating device having a supporting member ar-- ranged to be telescopically-received in 'saidso pedestal, and means for varying the 'eleva 'tion of said heating-device.

3. In combination, a frame having radi-' all extending bifurcated feet, a receptacle, ho ding-ring carried on the upper part of" said frame, a heating device, a supporting member for said heating device arranged to reciprocate within said frame, and meansfor varying the elevation of said heating de-a vice as desired.

4. In combination, a frame having radially extending portions arranged to receive a support, a receptacle holding ring carried by said frame, a edestal supported in said frame, a heating evice having a supporting member arranged to telescope in said pedes tal, and means forvarying the elevation of said heating device journaled in said pedestal.

tatable operating shaft therefor, and a pin:

ion arranged to travel thereon to permit," said device to be positively moved'by said, shaft or to move independently thereof. 4

7. In a heating appliance, a heating (18v vice, means for varying the elevation of the, same, a shaft, and means operable upon movement of said shaft permitting said heating device to move a re-determined amount independently of said shaft.

8. In a heating appliance, a heating de-f vice, a rack carried thereby, a' pinion arranged to engage said rack, an operatingshaft therefor, and means ermitting the" rotation of said pinion in ependently "of said shaft. 4 1

9. Ina heating appliance, aheat-ing dc vice, a rack for varying the elevation of the"? same, a pinion engaging said rack, an op'erfif' ating shaft for said pinion, and means per-" 5. In combination, a heatingdevice, allljiios mitting said pinion and rack to move a predetermined amount independently of said shaft.

, shaft.

11. In a heating appliance, a heating device, a rack arranged to be reciprocated to vary the position of said heating device, an operating shaft therefor having a threaded end, a pinion carriedon said end and engaging said rack, and stops carried by said shaft arranged to be engaged by said pinion to lock said pinion to said shaft.

12. In a heating appliance, a heating device, a casing inclosing the same, -a supporting member fixed to said casing, a pedestal arranged to receive said support telescopically, an operating member journaled in said pedestal, and a rack and pinion mechanism actuated by said operating member for varying the elevation of said heating device.

13. In a heating appliance, a heating device, a casing inclosing the same, a hollow supporting member fixed thereto, arack carried by said supporting member, a pedestal arranged to receive said supporting member telescopically, an operating member journaled in said pedestal, and means operable upon movement of said shaft for positively raising or lowering said heating device or permitting. the same to move through a pre-determined distance independently of said shaft.

'14. In a heating appliance, a heating device, a rack arranged to reciprocate to vary the position of said device, an operating shaft, a pinion carried thereby and engaging said rack, and means carried by said shaft for positively raising said rack or for permitting said rack and pinion to move independently of said shaft through a pre-determined distance.

15. In a heating appliance, a heating device, a rack carried thereby, a pinion engaging therewith and having a threaded bore, a shaft extending through said pinion and having a threaded end, a support for said shaft, a ratchet carried on one side of said pinion, a pawl carried on said support and engaging said ratchet, and stops carried on opposite sides of said pinion and said ratchet.

16. In a heating appliance, a heating device, means for varying the elevation of said device with respect to the object to be heated, and mechanism for rendering inoperative said means to permit said device to fall a predetermined amount by gravity.

17. In a heating appliance, a heating device, means for increasing the elevation of said device with respectto the object to be heated, and mechanism for rendering inoperative said means to permit said device to fall by gravity, and auxiliary means for insuring the positive lowering of said'device.

18. The combination with a heating device, of a frame supporting said heating device comprising legs, a utensil supporting ring fixed to said legs, and a pedestal relatively to which the heating device is adapted'to be moved.

19. In combination with a heating device, a franie adapted to support the same and comprising legs, a utensil supporting ring fixed to said legs and adapted to guide the heating device, a central pedestalsup ported within said frame beneath said utensil supporting ring, with respect to which the heating device is adapted to be moved.

20. In a heating appliance, the combination of a frame, a pedestal carried thereby, a telescoping member adapted to slide .in said pedestal, a heating device carried by said telescoping member, a rack fixed to said telescoping member, a threaded shaft mounted in said pedestal, a pinion adapted to travel on said shaft and to engage said rack to change the elevation of the same when the shaft is rotated, and means associated with said pinion whereby the rack is held in each position.v

21. In a heating appliance, a heating element, an element to be heated, means for effecting a movement of one of said elements relatively to the other, said means being adapted to release the movable element when desired, and means for holding said movable element in any desired position.

22. In a heating appliance, a heating element, an element to be heated and means forefl ecting a movement of one of said elements with respect to the other, comprising a single controlling shaft having a screw thread and collars adjacent each end of said screw thread, a pinion adapted to travel on said screw thread, a ratchet wheel loosely mounted upon said shaft adjacent said pinion, a pawl adapted to hold said ratchet wheel in any desired position and a toothed member fixed to the movable element and adapted to'be moved longitudinallyupon the rotation of said pinion with said shaft.

23. In combination, a chafing dish having transversely extending supports near the base thereof, a frame adapted to be removably mounted upon said supports, an electric heating disk movable with respect to said frame, operating mechanism for varying the position of said disk and carried in said frame, and a single operating,

member for actuating said operating mechaframe.

24. In combination e'heeting/deviee, an and means controlled by' the 'position of said operating shaft, h said shaft for varying device, said means bein'gtqarmnged so thet movement of the shaft-inon'e direction pos1- v tively moves said device and movement oitg i the shaft in the other direction permits. said 10' deviceto move independently of the shaft. In witness whereof, I have hereunto subscribed-my name 1n the presence of two witnesses. I

' HARRY W. DENHARD. g' Witnesses: H. L. Rocxwm W. E. SABGENT. 

